NAME

DESCRIPTION

The idea of tslib is to have a core library that provides standardised
services, and a set of plugins to manage the conversion and filtering
as needed.
The plugins for a particular touchscreen are loaded automatically by
the library under the control of a static configuration file,
/etc/ts.conf. /etc/ts.conf gives the library basic configuration
information. Each line specifies one module, and the parameters for
that module. The modules are loaded in order, with the first one
processing the touchscreen data first. For example:
module_raw input
module variance delta=30
module dejitter delta=100
module linear

MODULEPARAMETERS

variance
Tries to do it´s best in order to filter out random noise coming
from touchscreen ADC´s. This is achieved by limiting the sample
movement speed to some value (e.g. the pen is not supposed to move
quicker than some threshold).
This is a ´greedy´ filter, e.g. it gives less samples on output
than receives on input.
· Parameters:delta.
Set the squared distance in touchscreen units between previous
and current pen position (e.g. (X2-X1)^2 + (Y2-Y1)^2). This
defines the criteria for determining whenever two samples are
´near´ or ´far´ to each other.
If the distance between previous and current sample is ´far´,
the sample is marked as ´potential noise´. This doesn´t mean
yet that it will be discarded; if the next reading will be
close to it, this will be considered just a regular ´quick
motion´ event, and it will sneak to the next layer. Also, if
the sample after the ´potential noise´ is ´far´ from both
previously discussed samples, this is also considered a ´quick
motion´ event and the sample sneaks into the output stream.
dejitter
Removes jitter on the X and Y co-ordinates. This is achieved by
applying a weighted smoothing filter. The latest samples have most
weight; earlier samples have less weight. This allows to achieve
1:1 input->output rate.
· Parameters:delta.
Squared distance between two samples ((X2-X1)^2 + (Y2-Y1)^2)
that defines the ´quick motion´ threshold. If the pen moves
quick, it is not feasible to smooth pen motion, besides quick
motion is not precise anyway; so if quick motion is detected
the module just discards the backlog and simply copies input to
output.
linear
Linear scaling module, primarily used for conversion of touch
screen co-ordinates to screen co-ordinates.
· Parameters:xyswap.
Interchange the X and Y co-ordinates -- no longer used or
needed if the new linear calibration utility ts_calibrate is
used.

ENVIRONMENTVARIABLES

Latest versions of the Xorg tslib input driver use hal to configure the
touchscreen within Xorg. Environment variables are only needed for the
tslib commands.
TSLIB_TSDEVICE
If the default touchscreen device cannot be found, set the
TSLIB_TSDEVICE environment variable to the touchscreen device to
use.
Default: /dev/input/event0TSLIB_CONSOLEDEVICE
Tslib default console device.
Default: /dev/ttyTSLIB_CALIBFILE
Stores calibration data obtained using ts_calibrate.
Default: /etc/pointercalTSLIB_CONFFILE
Set a different location for the ts.conf configuration file itself.
Default; /etc/ts.conf.
TSLIB_FBDEVICE
Framebuffer device to use for the touchscreen support.
Default: /dev/fb0.
TSLIB_PLUGINDIR
Plugin directory for tslib.
Default: /usr/lib/ts/.

AUTHOR

This manual page was written by Neil Williams <codehelp@debian.org> for
the Debian(TM) distribution because the original program does not have
a manual page, but may be used by others. Permission is granted to
copy, distribute and/or modify this document under the terms of the GNU
General Public License, Version 2 any later version published by the
Free Software Foundation.
On Debian systems, the complete text of the GNU General Public License
can be found in /usr/share/common-licenses/GPL.